[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] IOMMU/x86: prefill newly allocate page tables
commit a81d9f9baa8a90db3f30d1f973addc30758a8068 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Mon Jul 25 15:38:22 2022 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Mon Jul 25 15:38:22 2022 +0200 IOMMU/x86: prefill newly allocate page tables Page tables are used for two purposes after allocation: They either start out all empty, or they are filled to replace a superpage. Subsequently, to replace all empty or fully contiguous page tables, contiguous sub-regions will be recorded within individual page tables. Install the initial set of markers immediately after allocation. Make sure to retain these markers when further populating a page table in preparation for it to replace a superpage. The markers are simply 4-bit fields holding the order value of contiguous entries. To demonstrate this, if a page table had just 16 entries, this would be the initial (fully contiguous) set of markers: index 0 1 2 3 4 5 6 7 8 9 A B C D E F marker 4 0 1 0 2 0 1 0 3 0 1 0 2 0 1 0 "Contiguous" here means not only present entries with successively increasing MFNs, each one suitably aligned for its slot, and identical attributes, but also a respective number of all non-present (zero except for the markers) entries. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx> Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Paul Durrant <paul@xxxxxxx> --- xen/arch/x86/include/asm/iommu.h | 3 ++- xen/drivers/passthrough/amd/iommu-defs.h | 4 +++- xen/drivers/passthrough/amd/iommu_map.c | 26 ++++++++++++++++++++----- xen/drivers/passthrough/amd/pci_amd_iommu.c | 2 +- xen/drivers/passthrough/vtd/iommu.c | 15 ++++++++------- xen/drivers/passthrough/vtd/iommu.h | 8 ++++++-- xen/drivers/passthrough/x86/iommu.c | 30 ++++++++++++++++++++++++++--- 7 files changed, 68 insertions(+), 20 deletions(-) diff --git a/xen/arch/x86/include/asm/iommu.h b/xen/arch/x86/include/asm/iommu.h index 4143723727..fc0afe35bf 100644 --- a/xen/arch/x86/include/asm/iommu.h +++ b/xen/arch/x86/include/asm/iommu.h @@ -146,7 +146,8 @@ void iommu_free_domid(domid_t domid, unsigned long *map); int __must_check iommu_free_pgtables(struct domain *d); struct domain_iommu; -struct page_info *__must_check iommu_alloc_pgtable(struct domain_iommu *hd); +struct page_info *__must_check iommu_alloc_pgtable(struct domain_iommu *hd, + uint64_t contig_mask); void iommu_queue_free_pgtable(struct domain_iommu *hd, struct page_info *pg); #endif /* !__ARCH_X86_IOMMU_H__ */ diff --git a/xen/drivers/passthrough/amd/iommu-defs.h b/xen/drivers/passthrough/amd/iommu-defs.h index 8a17697ea7..35de548e3a 100644 --- a/xen/drivers/passthrough/amd/iommu-defs.h +++ b/xen/drivers/passthrough/amd/iommu-defs.h @@ -446,11 +446,13 @@ union amd_iommu_x2apic_control { #define IOMMU_PAGE_TABLE_U32_PER_ENTRY (IOMMU_PAGE_TABLE_ENTRY_SIZE / 4) #define IOMMU_PAGE_TABLE_ALIGNMENT 4096 +#define IOMMU_PTE_CONTIG_MASK 0x1e /* The ign0 field below. */ + union amd_iommu_pte { uint64_t raw; struct { bool pr:1; - unsigned int ign0:4; + unsigned int ign0:4; /* Covered by IOMMU_PTE_CONTIG_MASK. */ bool a:1; bool d:1; unsigned int ign1:2; diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c index fa8fd6f800..7d4e0ba587 100644 --- a/xen/drivers/passthrough/amd/iommu_map.c +++ b/xen/drivers/passthrough/amd/iommu_map.c @@ -21,6 +21,8 @@ #include "iommu.h" +#include <asm/pt-contig-markers.h> + /* Given pfn and page table level, return pde index */ static unsigned int pfn_to_pde_idx(unsigned long pfn, unsigned int level) { @@ -113,9 +115,23 @@ static void set_iommu_ptes_present(unsigned long pt_mfn, return; } + ASSERT(!(next_mfn & (page_sz - 1))); + while ( nr_ptes-- ) { - set_iommu_pde_present(pde, next_mfn, 0, iw, ir); + ASSERT(!pde->next_level); + ASSERT(!pde->u); + + if ( pde > table ) + ASSERT(pde->ign0 == find_first_set_bit(pde - table)); + else + ASSERT(pde->ign0 == CONTIG_LEVEL_SHIFT); + + pde->iw = iw; + pde->ir = ir; + pde->fc = true; /* See set_iommu_pde_present(). */ + pde->mfn = next_mfn; + pde->pr = true; ++pde; next_mfn += page_sz; @@ -295,7 +311,7 @@ static int iommu_pde_from_dfn(struct domain *d, unsigned long dfn, mfn = next_table_mfn; /* allocate lower level page table */ - table = iommu_alloc_pgtable(hd); + table = iommu_alloc_pgtable(hd, IOMMU_PTE_CONTIG_MASK); if ( table == NULL ) { AMD_IOMMU_ERROR("cannot allocate I/O page table\n"); @@ -325,7 +341,7 @@ static int iommu_pde_from_dfn(struct domain *d, unsigned long dfn, if ( next_table_mfn == 0 ) { - table = iommu_alloc_pgtable(hd); + table = iommu_alloc_pgtable(hd, IOMMU_PTE_CONTIG_MASK); if ( table == NULL ) { AMD_IOMMU_ERROR("cannot allocate I/O page table\n"); @@ -726,7 +742,7 @@ static int fill_qpt(union amd_iommu_pte *this, unsigned int level, * page table pages, and the resulting allocations are always * zeroed. */ - pgs[level] = iommu_alloc_pgtable(hd); + pgs[level] = iommu_alloc_pgtable(hd, 0); if ( !pgs[level] ) { rc = -ENOMEM; @@ -784,7 +800,7 @@ int cf_check amd_iommu_quarantine_init(struct pci_dev *pdev, bool scratch_page) return 0; } - pdev->arch.amd.root_table = iommu_alloc_pgtable(hd); + pdev->arch.amd.root_table = iommu_alloc_pgtable(hd, 0); if ( !pdev->arch.amd.root_table ) return -ENOMEM; diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c b/xen/drivers/passthrough/amd/pci_amd_iommu.c index 02aea838ad..4ba8e764b2 100644 --- a/xen/drivers/passthrough/amd/pci_amd_iommu.c +++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c @@ -342,7 +342,7 @@ int amd_iommu_alloc_root(struct domain *d) if ( unlikely(!hd->arch.amd.root_table) && d != dom_io ) { - hd->arch.amd.root_table = iommu_alloc_pgtable(hd); + hd->arch.amd.root_table = iommu_alloc_pgtable(hd, 0); if ( !hd->arch.amd.root_table ) return -ENOMEM; } diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c index 26e3a84abe..28dc54b6bf 100644 --- a/xen/drivers/passthrough/vtd/iommu.c +++ b/xen/drivers/passthrough/vtd/iommu.c @@ -334,7 +334,7 @@ static uint64_t addr_to_dma_page_maddr(struct domain *domain, daddr_t addr, goto out; pte_maddr = level; - if ( !(pg = iommu_alloc_pgtable(hd)) ) + if ( !(pg = iommu_alloc_pgtable(hd, 0)) ) goto out; hd->arch.vtd.pgd_maddr = page_to_maddr(pg); @@ -376,7 +376,7 @@ static uint64_t addr_to_dma_page_maddr(struct domain *domain, daddr_t addr, } pte_maddr = level - 1; - pg = iommu_alloc_pgtable(hd); + pg = iommu_alloc_pgtable(hd, DMA_PTE_CONTIG_MASK); if ( !pg ) break; @@ -388,12 +388,13 @@ static uint64_t addr_to_dma_page_maddr(struct domain *domain, daddr_t addr, struct dma_pte *split = map_vtd_domain_page(pte_maddr); unsigned long inc = 1UL << level_to_offset_bits(level - 1); - split[0].val = pte->val; + split[0].val |= pte->val & ~DMA_PTE_CONTIG_MASK; if ( inc == PAGE_SIZE ) split[0].val &= ~DMA_PTE_SP; for ( offset = 1; offset < PTE_NUM; ++offset ) - split[offset].val = split[offset - 1].val + inc; + split[offset].val |= + (split[offset - 1].val & ~DMA_PTE_CONTIG_MASK) + inc; iommu_sync_cache(split, PAGE_SIZE); unmap_vtd_domain_page(split); @@ -2168,7 +2169,7 @@ static int __must_check cf_check intel_iommu_map_page( if ( iommu_snoop ) dma_set_pte_snp(new); - if ( old.val == new.val ) + if ( !((old.val ^ new.val) & ~DMA_PTE_CONTIG_MASK) ) { spin_unlock(&hd->arch.mapping_lock); unmap_vtd_domain_page(page); @@ -3058,7 +3059,7 @@ static int fill_qpt(struct dma_pte *this, unsigned int level, * page table pages, and the resulting allocations are always * zeroed. */ - pgs[level] = iommu_alloc_pgtable(hd); + pgs[level] = iommu_alloc_pgtable(hd, 0); if ( !pgs[level] ) { rc = -ENOMEM; @@ -3115,7 +3116,7 @@ static int cf_check intel_iommu_quarantine_init(struct pci_dev *pdev, if ( !drhd ) return -ENODEV; - pg = iommu_alloc_pgtable(hd); + pg = iommu_alloc_pgtable(hd, 0); if ( !pg ) return -ENOMEM; diff --git a/xen/drivers/passthrough/vtd/iommu.h b/xen/drivers/passthrough/vtd/iommu.h index 09ec09fe27..7c3fe40150 100644 --- a/xen/drivers/passthrough/vtd/iommu.h +++ b/xen/drivers/passthrough/vtd/iommu.h @@ -253,7 +253,10 @@ struct context_entry { * 2-6: reserved * 7: super page * 8-11: available - * 12-63: Host physcial address + * 12-51: Host physcial address + * 52-61: available (52-55 used for DMA_PTE_CONTIG_MASK) + * 62: reserved + * 63: available */ struct dma_pte { u64 val; @@ -263,6 +266,7 @@ struct dma_pte { #define DMA_PTE_PROT (DMA_PTE_READ | DMA_PTE_WRITE) #define DMA_PTE_SP (1 << 7) #define DMA_PTE_SNP (1 << 11) +#define DMA_PTE_CONTIG_MASK (0xfull << PADDR_BITS) #define dma_clear_pte(p) do {(p).val = 0;} while(0) #define dma_set_pte_readable(p) do {(p).val |= DMA_PTE_READ;} while(0) #define dma_set_pte_writable(p) do {(p).val |= DMA_PTE_WRITE;} while(0) @@ -276,7 +280,7 @@ struct dma_pte { #define dma_pte_write(p) (dma_pte_prot(p) & DMA_PTE_WRITE) #define dma_pte_addr(p) ((p).val & PADDR_MASK & PAGE_MASK_4K) #define dma_set_pte_addr(p, addr) do {\ - (p).val |= ((addr) & PAGE_MASK_4K); } while (0) + (p).val |= ((addr) & PADDR_MASK & PAGE_MASK_4K); } while (0) #define dma_pte_present(p) (((p).val & DMA_PTE_PROT) != 0) #define dma_pte_superpage(p) (((p).val & DMA_PTE_SP) != 0) diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c index b4d9da7cf8..f671b0f2bb 100644 --- a/xen/drivers/passthrough/x86/iommu.c +++ b/xen/drivers/passthrough/x86/iommu.c @@ -26,6 +26,7 @@ #include <asm/hvm/io.h> #include <asm/io_apic.h> #include <asm/mem_paging.h> +#include <asm/pt-contig-markers.h> #include <asm/setup.h> const struct iommu_init_ops *__initdata iommu_init_ops; @@ -534,11 +535,12 @@ int iommu_free_pgtables(struct domain *d) return 0; } -struct page_info *iommu_alloc_pgtable(struct domain_iommu *hd) +struct page_info *iommu_alloc_pgtable(struct domain_iommu *hd, + uint64_t contig_mask) { unsigned int memflags = 0; struct page_info *pg; - void *p; + uint64_t *p; #ifdef CONFIG_NUMA if ( hd->node != NUMA_NO_NODE ) @@ -550,7 +552,29 @@ struct page_info *iommu_alloc_pgtable(struct domain_iommu *hd) return NULL; p = __map_domain_page(pg); - clear_page(p); + + if ( contig_mask ) + { + /* See pt-contig-markers.h for a description of the marker scheme. */ + unsigned int i, shift = find_first_set_bit(contig_mask); + + ASSERT((CONTIG_LEVEL_SHIFT & (contig_mask >> shift)) == CONTIG_LEVEL_SHIFT); + + p[0] = (CONTIG_LEVEL_SHIFT + 0ull) << shift; + p[1] = 0; + p[2] = 1ull << shift; + p[3] = 0; + + for ( i = 4; i < PAGE_SIZE / sizeof(*p); i += 4 ) + { + p[i + 0] = (find_first_set_bit(i) + 0ull) << shift; + p[i + 1] = 0; + p[i + 2] = 1ull << shift; + p[i + 3] = 0; + } + } + else + clear_page(p); iommu_sync_cache(p, PAGE_SIZE); -- generated by git-patchbot for /home/xen/git/xen.git#master
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